Not really any such thing as an "entry level" liveaboard
cruising boat - but that does not matter! I am guessing that by that you mean something without lots of bells and whistles / mod cons.
You've got the budget
and boat length defined (although a big difference between 30 and 40 foot, for 2 of you and wanting "comfort" I would be looking at 35 to 40, plus or minus a couple of feet depending on the boat design) - pretty much anything you can buy will fit your requirements, or at least could do with the tweaks and mods all of them will need. Likely the 3rd factor that will choose the boat is your location and simply what is for sale
(in budget and size) at the time you want her (doesn't sound like you have a budget big enough to be going on many - or any! - buying
trips).......boats is all about compromises anyway - as long as you keep away from the extremes pretty much anything will do - so don't get too hung up on specific models.....go for the best condition at the price
you can find that fits your basic needs (inlcuding the berth size!) - when you want her.
Condition will be the main factor in determining seaworthiness and reliability
(along with ability of Skipper
and crew), and sound like you are willing to put some sweat equity into acheiving those - the trick will be not to buy something needing more of that than expected (a couple of years can slip by quickly).